Differentiating rheumatoid and psoriatic arthritis: a systematic analysis of high-resolution magnetic resonance imaging features—preliminary findings

Abstract

Background Because of overlapping phenotypical presentations, the diagnostic differentiation of rheumatoid arthritis (RA) and psoriatic arthritis (PsA) remains challenging. Thus, this study aimed to examine the diagnostic value of distinct imaging features obtained by high-resolution 3-T MRI for the diagnostic differentiation. Materials and methods Seventeen patients with PsA and 28 patients with RA were imaged at high resolution using 3-T MRI scanners and a dedicated 16-channel hand coil. All images were analyzed according to the outcome measures in rheumatology clinical trials’ (OMERACT) RAMRIS (Rheumatoid Arthritis Magnetic Resonance Imaging Score) and PsAMRIS (Psoriatic Arthritis Magnetic Resonance Imaging Score) for the presence and intensity of synovitis, flexor tenosynovitis, bone edema, bone erosion, periarticular inflammation, bone proliferation, and joint space narrowing. Next, odds ratios (OR) were calculated to determine the strength of the associations between these imaging features, demographic characteristics, and the outcome RA vs. PsA. Results PsA could be differentiated from RA by extracapsular inflammatory changes (PsAMRIS sub-score “periarticular inflammation”), with low odds for the presence of RA (OR of 0.06, p < 0.01) at all metacarpophalangeal (MCP) joints. A prediction model informed by the items that were strongest associated with the presence of RA or PsA demonstrated excellent differentiating capability with an area under the curve of 98.1%. Conclusion High-resolution imaging is beneficial for the identification of relevant imaging features that may assist the clinical differentiation of inflammatory conditions of the hand. At the MCP level, extracapsular inflammatory changes were strongly associated with PsA and may consequently allow the imaging differentiation of PsA and RA. Electronic supplementary material The online version of this article (10.1007/s00256-020-03588-5) contains supplementary material, which is available to authorized users.

Anatomical analysis of inflammation in hand psoriatic arthritis by Dual-Energy CT Iodine Map

“…However, since tendon sheath runs near bones, pulleys, volar plates and other fibrous structures, the enhancement along the tendon sheath may indicate secondary tenosynovitis from classical/functional enthesitis. Hence, our results may coincide with the hypothesis that primary inflammatory sites of PsA are enthesis, which is different from RA [7].…”

Relationship between iodine‐enhanced dual energy‐computed tomographic findings and ultrasonographic findings for psoriatic arthritis

“…PsA from RA. Abrar et al 17 Recently, we reported that iodine uptake correlated with a scoring system for the local inflammatory lesions as well as scores of visual analog scale for pain in PsA. 16 However, iodine uptake did not correlate with PACE scores in our study.…”

“…Phenotypic overlap sometimes leads to difficulties distinguishing PsA from RA. Abrar et al 17 . examined the images obtained from high‐resolution 3‐Tesla MRI scanners and a dedicated 16‐channel hand coil for 17 PsA patients and 28 RA patients.…”

Magnetic resonance imaging of rheumatological diseases

“…Early PsA can be difficult to differentiate from early RA both clinically and with imaging. Abrar et al showed that with high-resolution MRI extracapsular inflammation was more common with PsA, while flexor tenosynovitis was associated with RA at the MCP joint [82]. Peritendinitis of the extensor tendon at the MCP joints where the tendon sheath is absent, thought to represent functional enthesitis between the metacarpal head and extensor digitorum tendon, is more common in PsA than RA [3].…”